They were stories that they were working on developing a Raven show around the time Smallville ended, but I don't think anything ever became of it.
I love Raven, but I don't think it's a concept that would work for television. Raven was raised in another dimension, and taught to use her magic there. When she was a teen, she was ready to fight evil.
TV would have her raised in small town America, and not aware of her special nature until the events of the pilot. She would meet a wise mentor who can tutor in learning to use her magical abilities. It would be an age of discovery storyline.
The problem is, despite being half demon, the show comes across as a witch story. And with the exception of Bewitched
, witches have no staying power on television.
It's possible they even recognized the similarity, because they did have the series The Secret Circle
that was a witch story come out a couple of years ago, and it didn't last.